As rumored last week, Microsoft made available on April 18 a public beta of its Office 365 bundle of Microsoft-hosted applications.

Office 365 will include updated versions of SharePoint Online, Exchange Online, Lync Online, Office Web Apps and an optional Office 2010 Professional Plus software package, all available as via subscription. It will bring many, though not all, of the capabilities in the on-premises versions of SharePoint 2010, Exchange 2010 and Lync 2010 to cloud users. (Office 365 is Microsoft-hosted, but not yet hosted on Windows Azure, for the record.)

In October 2010, Microsoft introduced an invitation-only, limited beta of Office 365 -- the successor to Microsoft's Business Productivity Online Suite (BPOS), Live@Edu offering and its Office Live Small Business service. Microsoft officials said that more than 100,000 organizations signed up for the beta.

Those interested in kicking the tires of the new public beta, available in 38 markets and 17 languages, can sign up at http://www.Office365.com.

Update: Those who are signing up for new/first-time Office 365 accounts are being told they won't actually be added to the beta for two weeks, according to @Karucifer. He's right. I've asked Microsoft why there's a delay. and will add any information I receive to this post. Here's the official response from a spokesperson: "If the tremendous interest we saw in the private beta is any indication, we expect a tremendous response to the public beta, and we want to ensure our customers have a great experience getting into the beta.” Those already testing Office 365 are being upgraded to the new beta automatically, Microsoft execs said.

Microsoft also announced plans on April 18 to take the wraps off the Office 365 Marketplace. The marketplace will highlight partner apps and services for Office 365. There will be 100 apps and 400 professional services in the marketplace to start. The Office 365 marketplace can be found here.

Microsoft execs are continuing to promise Office 365 will drop its beta tag later this year. I continue to hear that will happen in early June.

Microsoft officials said last year that the company is planning to add the Dynamics CRM Online offering to Office 365 at some point in 2011, but have offered no additional details.

Update 2: UK VAR software manager RIchard Gibbons has a good summary of some of the "license mobility" changes Microsoft is making to accommodate users who want to run Microsoft applications in a mix-and-match way across the cloud and on-premises servers.